


Interdimentional

by SigynNightmare



Category: Undertale (Video Game)
Genre: Dadster vs Handplates!Gaster, Dont touch my cinnamon rolls!, Evil W. D. Gaster, Gen, Good W. D. Gaster, Headcanon, Mild Hurt/Comfort, No Beta, One Shot, S-1 and 2-P need love, We Die Like Men, Why are you like this Gaster?
Language: English
Status: Completed
Published: 2019-02-04
Updated: 2019-02-04
Packaged: 2019-10-22 12:12:25
Rating: Not Rated
Warnings: Major Character Death
Chapters: 1
Words: 3,195
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17662415
Author URL: https://archiveofourown.org/users/SigynNightmare/pseuds/SigynNightmare
Summary: My headcanon of what would happen if Dadster meets the Gaster of Handplates. There is going to be a brutally murder of a scientist, fluff feelings and a happy ending for S-1 and 2-P, so read it at your own risk.





	Interdimentional

**Author's Note:**

> I love the idea of a good and caring Dr Gaster and as much I adore Handplates I always feel bad for Sans and Papy so I created this to vent some of the frustration, please dont take it too seriusly.

This wasn't supposed to happen.

Gaster actually didn't know what exactly had gone wrong, but that didn't mattered as he was being disintegrated and the only thing he could thing was  _Gods, no. Why this had to happen when Sans is here? Why not when I was alone…?_ as he saw the panic rose in his oldest son and tears begin to form in his eyes.

Sans had tried to get close to him calling "Dad!" in a scared tone, but Gaster had pushed him back whit all the force he could muster as he didn't wanted his son to get hurt, making the young skeleton hit the wall, his magic holding him so he couldn't get up and try again. He didn't know if this was only affecting him or if it would affect his son too if he get closer to him.

His desire to protect his son was stronger than the fear and pain he was feeling as his body continued to pixelate, vanishing in the air.

"Listen, Sans. You have to take care of your brother. ¿Ok?" He said forcing himself to sound normal, even if he wanted to scream. "So you have to be strong. That means no more going to the ruins or playing in the snow for many hour, also don't try to cook yourself, go to Grillby if you are in trouble, even if its night, he will be for both of you every time you need him. Also make sure that Papyrus doesn't get into many problems and that he always brush his teeth…and…and…" He stopped when the tears started to brake his voice. There were so many things he wanted to say to his sons! And he couldn't. There wasn't time.

That was when it hit him.

He would not see his sons grow.

He was leaving his sons as orphans.

"I love you" He babbled between sobs, his soul screaming for the pain, as he could see the sorrow grow in his sons features as he screamed and tried to get free from the embrace of his magic.

"No! No! Dad!, Please!, Don't leave us!, Please!" the begs of his son broke his heart so he could only try a smile to comfort him, even if he knew it was a futile intent.

"Don't forget" That was the last thing he said before the darkness devoured him and everything was gone; the echoes of the scream of agony that his son produced being the thing that accompanied him in his last moments.

* * *

Everything was dark.  _Empty_.

Just him in an eternal darkness.

He didn't knew how much time he had passed floating –Or falling? He really didn't know as both sensations felt in a similar way to him– in the abyss. He also didn't knew why was he in this place but sometimes he wondered if it was a punishment for something he had done, and if it was like that what was the horrible thing that he have done to deserve this? But no answer came to his mind as he didn't know who he was or what he was.

It felt as he was nothing in the dark. As he existed, whit no purpose or justification, just being, in the same way that the darkness around him was.

But that change from a moment to another as he finally met the end of his long fall. He had thought that it would hurt crashing into the floor but it hadn't. He had  _bounced._  As if he wasn't something solid anymore. That picked his curiosity and tried some movements to see if he was as gelatinous as he felt when he had touched the floor.

He extended his arms upwards, stretching his limbs as far as he could, then dropped them and placed his hands as close to his face as he could, to appreciate them, noticing for the first time that he had gaps in his hands. He cautiously touch the bone of one of his hands whit his middle finger. Yep, solid bone. Not some kind of goo as he had feared.

Letting a sight escape he turned and began to explore his surroundings. His curiosity growing whit every step he made. There were things inside the darkness, just that it were in the same tone of dark that everything else so he couldn't see them, just felt them as he bumped into them. It felt somewhat familiar even if he couldn't see his surroundings.

One of his eyes was broken so he only had half of a vision but he was sure, he had known this place. He felt as if this place was somewhere he had stayed for a long period of time. Maybe...Maybe, this was his home.

The idea made him happy and so he smiled that broken and terrific smile of his, even when he intended it to be a sign of how happy he was.

He had experimented whit his own magic instinctively, so even if it had taken a lot of time, he had found a way to control the shadows in the darkness. He had found that if he concentrated enough he could made them turn into a coat and made his surroundings visible. Thanks to this he had learned that his home was a laboratory and not a house as he had been imagine that it would, but it was actually very cool so it was acceptable.

He also had found something that he was sure didn't existed in his laboratory before…before this, a small pond that has a similar function as a TV as it allowed him to see things that were happening in another times or worlds.

He had taken the habit to sit a few steps from the edge of the pond a couple of hours a day –or what he thought was a day. As it was difficult to define time inside the abyss– just to observe what happened in it. He hadn't found something that pick up his attention in the many hour he had watch, but that change when he found a version of himself.

He had recognized himself in the man whit the face in flames. How? Well he didn't know, so don't ask. He just knew.

That other version of himself was a scientist. So that meant that he was also a scientist, right? After all, he  _did_  live in a laboratory. Thanks to that other skeleton he also had learned that his name was W.D. Gaster o Winding Gaster, such a strange name, so he decided that he would be referring to himself as Gaster, just like the other version of himself.

That other Gaster was looking for something. But Gaster didn't know what that was as the pond hadn't show him nothing about that. He watched more time, all the time, just wanting to know who he was.

He observed whit curiosity how he cut his own bones and end whit the same kind of holes that he had. It made him wonder if he had done something similar, as well to wonder for what were the extracts of bone, because it had to have a reason behind the painful procedure.

He watched amazed as the other Gaster created babies from those pieces of bone. That was so amazing! Creating a living creature whit a soul was something very difficult and it actually had been a dead end theory for years! And he had made it!

But his pride and happiness didn't last long, it slowly turned into horror as he continued to watch the events unfold into a nightmare. That other Gaster was using the boys – _his own sons_ – as test subjects!

He was hurting them!

He was broking them!

 _He marked them as things_!

That other Gaster was a beast. He was…he was…as cruel and barbarous as the humans!

He wasn't like that! He would have never hurt his sons! He would have never treated Sans and Papyrus like they were less than him! His boys were his world!

Oh, gods. His boys. His babies.  _His sons!_

Panic, pain, sorrow. He felt all that when his memories returned to him. He screamed as his magic got out of control and the shadow consumed everything once again.

 **"NO! Give them back!** " He hollowed as the images disappeared and the rage filled him, his magic exploded and destroyed the entire place. He was scared. But not for him, but from his beautiful children. The children that he had leave as orphans in his own world and the two babies that were being tortured by the hand of that other Gaster that was supposed to be their father.

He lost control.

And it felt different that when he had lost his calm before, when the human broke his skull and threatened his older son, it felt darker and much more dangerous, his own projections felt more bestial and fierce than ever before.  _He_  was way more savage than he was before the experiment had gone wrong.

And that actually was the reason why he couldn't gain his control once again in a very, very, long time. So when he actually was able to submit the darkness to his wishes and turn everything back as it was before, and actually being able to see the pond once again it had passed much time for his sons as well.

They were closer to the age they had in his old world. He had to force himself to breath to stopped himself from panicking at the idea that his babies where trapped in that hell for  _years_  before reason informed him that the other Gaster has made them grow much faster than he had with his own sons, so it actually it only had been months, and no years as he feared.

He needs to find a way to help them.

And so Gaster started to experiment once again.

* * *

"It's time for a lesson"

Those words just made S-1 bad feeling go up, all the 'lessons' that Gaster had given them, resulted in one of them hurting, usually his brother, because he was the most resistant to abuse. Frightened he followed the instructions of the major, feeling his anxiety increase as the elder explained what the blue magic was, beginning to tremble when he was locked in a cage of bones created by the scientist.

"Now let's go to the point"

S-1 watched in horror as the other began to push his brother against the walls of the room, hitting him hard, breaking his bones, hurting him.

"Dont do it! Stop! "He beg even knowing that the other was not going to stop. He felt panic grow at the amount of injuries that the other was causing his brother, beginning to believe that he was going to kill him. "Please... stop...please…"

Gaster was speaking slowly, calmly, like he was not hurting his brother. But then something happened, something that neither had been expecting.

Purple energy covered 2-P, Gaster lost control of the magic and emitted a surprised gasp, but Sans only have eyes to his brother, he watched anxiously as the purple energy put his brother in the floor very carefully, almost as if the magic was trying to not hurt more the little skeleton.

Then, another unrespecting thing happen.

Darkness started to leak out from the walls and a somber figure materialized in the middle of the room. He was Gaster, they have the same face, but he was also very different. This other Gaster was dressed in a black coat, had two long fissures in his skull and his eyes shone violet and wore a terrifying smile, a grimace sadistic and brutal.

" **HoW DAre YoU to HUrt ThEM?!"** The newcomer growled. His voice was distorted, angry and dark. It make S-1 flinch and sob, even if that rage wasn't directed at him.

"Wha…What are you?" The scientist asked in a trembled whisper, he was scared, terrified at the view of this other version of himself who was feral and was obviously very pissed at him. He could see the summons starting to form at his back and they were nothing like his, as they were wilder and more savage looking.

" **OH WhERe aRe mY maNErS"** The specter allow his smile to grow  **"My nAMe iS W. D gaSteR"** He crackled at the face that his counterpart made.  **"NOt FrOM tHIs WorLD, OBviOSLy"** he said before using his magic to push the other skeleton whit enough force to actually brake the wall and make it reach the corridor.

" **Sans, stay whit your brother while I take care of the trash"** He said kindly to his older son, making his features softer and paternal, ignoring the flinch Sans give when he move closer. He knew he had scare the boy but actually couldn't help it, he was furious at the other version of himself as he had tried to kill his youngest and had immediately intervened. He touched in a soft way the head of his son as he moved into the corridor to deal whit the fool that had thought of hurting his children was a good idea.

S-1 didn't understand. The new skeleton was weird, he had said that he was Gaster, just from another world. He had been kind and had saved 2-P, preventing him for being hurt for the Gaster of this world. He had defended them. He also had called him ´Sans´…

He shakes his head. He doesn't have time for this. He has to help his brother!

He ran and kneel at the side of the other boy, starting to heal him, ignoring the scrams of pain that reached his ears form time to time.

" **Oh, dear god."**

S-1 flinched and turn to face the older skeleton, his posture tense, but relaxed lightly as he saw the Gaster that have saved 2-P, the other male seemed concerned and surprised.  **"Sans…Are you a healer?"** He asked as he moved, slowly, carefully, until he were knelling at his side, his left hand touching his brother´s head.

S-1 nodded once, eying him with suspicion.

This Gaster let out a sigh of relief.  **"That's good...very good. After all, I´m not a good healer and I don't trust any doctor of this world whit Papyrus health if they actually were letting** _ **him**_ **hurt you guys"** He said whit sadness as it hurt of thinking of his friends and the King being evil, but if the version of himself was a cruel beast it was possible that all the others were just as bad as him.

"You are not going to hurt us?" S-1 asked a little confused by the way this Gaster called him and his brother by something similar to names.

" **Of course not."**  Gaster scoffed a little offended, but understanding the why behind the question _ **.**_ **"You are my sons."**

" **I will never hurt you. You mean the world to me"**  He explained seeing the black face of the younger skeleton, and he mean it. His sons where the most precious thing in the world to him, everything else could burn in hell for all he care if he could save them.

"What´s ´son´?" A tired voice asked, forcing the two skeletons to focus in the third one. 2-P had opened his eyes, but he had this tired aura surrounding him.

" **Oh, well. ´Son´ means …"** Gaster started, but stopped before he smiled. He had intended to give Papyrus a full definition of the dictionary, but decide to not to, because it actually that wasn't what ´Son´ maenad to him.  **"It´s the word that adults use to call their more beautiful treasure in the entire world"** He said warmly as he pet the boy in a loving way.

His eyes were glowing in a purple and warm light that eased the two boys as they recognized as the same glow that they made when they were together. It was kind to see it in another person.

"Oh…"The hurt boy said before smiling and closing his eyes, going to sleep, relaxing now that he felt safe.

"What are going to do now?" S-1 asked once he had healed his brother.

" **I think we should go to my house. Both of you need a safe place to rest"** Gaster said, before taking Papyrus carefully between his arms, accommodating his baby son against his chest. It would have been easier to holding the younger skeleton whit his magic but he didn't want to upset Sans.  **"Can you walk, Sans?"**  He asked to his older son, concern filling his eyes and tinted his voice.

The boy nodded.

Gaster move Papyrus to his left arm, changing the position of the boy so he could take the hand of his other son. He extended his hand and after a small moment of doubt, Sans accepted. Gaster smiled a little, not noticing that the boy shudder at the sight.

They started to walk, ignoring the mountain of dust that was the only evidence that the Gaster of this world had existed as it wasn't important for neither of them. Gaster actually had to change course a couple of times, because this laboratory was slightly different from his, but in the end he could find the exit and they went to the address where Gaster had lived in his world, finding his house without problems. Although this was also a little different, it felt a bit neglected, which let the older skeleton know that his counterpart spent too much time in his laboratory, just as he had done before having his children.

The entire journey had Sans gaping at everything, but he didn't left Gaster side as the older one was still holding his brother.

" **Umm"** Gaster used his magic to open the lock in his door, making his son to cross the threshold, before turning the lights on.  **"Come on, Sans. We need to get some clothes for you and Papyrus, before getting you on bed. Both of you need to rest"**

"Why you call me that?" S-1 asked a little confused.

" **Huh?"** That made Gaster stop in the middle of the stairs. He looked down to his son, a little confused before realization come to him.  **"Oh. He didn't give you names, right? He called you things."** Anger colored his voice and his eyes glowed purple, before he let a sight and his posture relaxed, before saying whit sadness  **"Sans is your name, he is Papyrus. You are my sons.** _ **Not things**_ **."**

" **In my world you live whit me, as my equals. Not some kind of test subjects."** He added before get the child into his room and making him seat in the bed, putting his youngest at his side, then went into his closet, starting to pick clothes that he thought his children could use it for the time being.

"I see" S-1 answered whit a thoughtful stance. It sound too good to be true but…but maybe his brother was right and things could get better

He prayed for his brother to be right.


End file.
